At the time, senior officers said they shared concerns about the capacity of younger children to give "informed consent" to be searched.

The Scottish Police Authority meeting was called after BBC Scotland reported that the data released by Police Scotland had shown 356 children aged under 12 had been subject to "consensual" searches, despite assurances from the force that the practice would cease.

Image caption
Police officers have defended the use of stop and search

The chief constable said: "I think the BBC reported it as accurately as they could do.

"But the data was not 100% accurate and needed further interpretation."

The BBC was not told that the figures from the police were inaccurate when they were released.

It emerged during the meeting that Police Scotland had also failed to tell the watchdog about its concerns over the data.

This information was released under the freedom of information act on the express instruction of the Freedom of Information Commissioner in ScotlandSir Stephen House, Chief Constable

Senior officers blamed a "clunky" ICT system and problems with the recording of incidents for the inaccuracies.

Sir Stephen said: "This information was released under the freedom of information act on the express instruction of the Freedom of Information Commissioner in Scotland.

"We challenged whether it should be released because we were not 100% certain of the accuracy, we wanted more time to work on it. We were told 'no, release it now'.

"It wasn't a consensual release, it was a legislation release."

The commissioner did not make a formal decision, so it is inaccurate to say Police Scotland was compelled to disclose the information to you (BBC Scotland): it did so voluntarilyMargaret Keyse, Scottish Information Commissioner's office

But Margaret Keyse, head of enforcement at the Scottish Information Commissioner's office, said it had not forced the police to release the data.

She said that the commissioner must investigate any appeals it gets under the Freedom of Information Scotland Act and she could compel an authority to take action such as disclosing information.

However, she told BBC Scotland: "In your case, the commissioner did not make a formal decision, so it is inaccurate to say Police Scotland was compelled to disclose the information to you: it did so voluntarily."

Ms Keyse added that the Information Commissioner's role was to consider whether data held by the police should be released in the public interest.

She said the commissioner did not have the power to question or challenge the accuracy of the information.

"While FOI does not, of itself, ensure that the information held is accurate its strength lies in the fact that others can access the information needed to hold Scottish public authorities to account," she said.

Analysis

By Marc Ellison, BBC Scotland data journalist

The acquisition of the 2014 stop-search data by BBC Scotland took many months, and was only finally released after an intervention by the Scottish Information Commissioner.

Chief Constable Sir Stephen House has now called the data "inaccurate" - data that should never have been released to the media.

In its defence, Police Scotland did acknowledge in mid-2014 that thousands of records had been corrupted.

In an October 2014 letter, the force stated that "the data assurance work is not due for completion until December 2014".

The stop-search data was finally received by BBC Scotland in mid-January 2015 - at which point no mention was made of any residual errors in the data.

The accompanying note only had one caveat - to disregard any ages outwith 1-90.

Friday's meeting between Police Scotland and the force watchdog has raised some alarming issues.

Firstly, that the stop-search database is a "clunky" and error-ridden system. This revelation will cast a long shadow, putting into doubt any further stop-search statistics released by the force.

Secondly - and perhaps more disturbingly - Police Scotland said they would not have volunteered the data, but were only compelled to by the Information Commissioner.

This could raise concerns over what data Police Scotland will willingly release through freedom of information laws in the future.

Assistant Chief Constable Nelson Telfer told the Scottish Police Authority that analysis of the figures now suggested that only 18 of the searches had been contrary to force policy.

A number of searches had been carried out under legislative powers, while others had taken place when a parent or guardian was present.

He said IT problems with data collection meant many other incidents of consensual stop-searches of children had been incorrectly recorded.

The chief constable said IT problems had been identified before the data was released to the BBC.

Following questions on why the Scottish Police Authority was not made aware of the 18 searches until now, Sir Stephen said he accepted that Police Scotland "made mistakes".

Image copyrightPolice ScotlandImage caption
BBC Scotland revealed last week that police were continuing to carry out consensual stop-searches on under-12s

Following the SPA meeting, Scottish Liberal Democrat leader Willie Rennie called for an independent audit of police stop-and-search figures.

He said: "First police chiefs told parliament consensual stop-and-search of young people would end, and it didn't.

"Now they have told the SPA that the Information Commissioner compelled them to hand over inaccurate information to the BBC, when they didn't.

"Why has the chief constable allowed this to descend into chaos? It's time police chiefs were straight with the public."

Sir Stephen had begun the meeting by calling for a non-partisan debate on the issue of stop-search powers.

Emotive issue

He said the policy would continue to be an emotive issue.

A balance had to be struck between the rights of the individual and ensuring the community was kept safe, Sir Stephen said.

The police intend to consult on ending non-statutory or "consensual" stop-and-search for all age groups.

But they believe this will leave gaps in their ability to protect the public that must be filled.